Williams John TITAN T-51 MUSTANG N751TX

Summary

On 21 July 2024 at about 21:54 local time, a Williams John TITAN T-51 MUSTANG registered N751TX was involved in an accident near Geneva, Ohio, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

21 July 2024 at 21:54

Classification

Accident

Location

Geneva, Ohio, United States

Nearest airport

Germack Airport (7D9)

Coordinates

41.7791, -80.9069

Aircraft

Williams John TITAN T-51 MUSTANG

Registration

N751TX

Category

Airplane

Year built

2004

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Geneva → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA24FA310

1 person died.

A sudden propeller overspeed and subsequent separation of the propeller blades and hub, while maneuvering at high speed and at low altitude, which resulted in a collision with a tree during the subsequent forced landing attempt.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot, who was the builder of the experimental amateur-built airplane, was conducting a post-maintenance test flight. After performing several aerobatic maneuvers near the airport, the pilot began a high-speed low pass over the runway. Upon passing most of the runway, the airplane began a climb. A witness heard the engine go to a high rpm and then saw the entire propeller hub break apart. After the propeller hub fractured and separated, the airplane began a left turn toward a road. While maneuvering toward the road, the airplane’s left wing impacted a tree and the airplane subsequently rolled over and impacted terrain. Onboard recorded data revealed that, at the time the propeller separated, the engine was operating at 6,813 rpm, which equated to a propeller speed of 3,585 rpm. This speed was considerably in excess of the propeller blade blank manufacturer’s limit of 2,100 rpm. This speed would have produced a centrifugal force that was more than 3 times the design limit of the propeller blade blanks. Further examination of the onboard data revealed that, around the time of the propeller overspeed, the airplane was traveling at an airspeed about 223 miles per hour (mph); the published never-exceed speed (Vne) for the airplane was 215 mph. The data also revealed a sudden decrease in the longitudinal load factor, consistent with a sudden deceleration of the airplane, followed shortly thereafter by the longitudinal load factor returning to normal. A possible reason for the deceleration was a sudden increase in drag from the propeller blades moving to low pitch. This was followed by a reduction in drag on the airplane, which was likely due to the propeller separating from the airplane. Postaccident examination of the propeller governor, governor adapter, and the propeller gearbox revealed no evidence of any preacident mechanical failures or malfunctions that would have precluded normal operation. Ultimately, the reason for the propeller overspeed could not be determined based on available information.

Quoted verbatim from the NTSB record.